This section provides background information to facilitate a better understanding of the various aspects of the disclosure. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.
Water supply systems that obtain water from underground water tables or from surface waters can have numerous water quality problems. In some areas it is common for the raw water to have high amounts of dissolved calcium and magnesium hardness. In potable water applications it is common to pass some of the well or surface water thru an injector creating a vacuum that draws a solution containing a disinfectant chlorine compound such as sodium hypochlorite into the injector so that it mixes into the water to be treated. Typically the well or surface water has a pH that is near neutral and the hypochlorite solution has a high pH. When the two solutions mix in the injector, the pH of the combined solution is higher than that of the water being treated and calcium/magnesium deposition occurs. The mineral deposition interferes with the performance of the injector and the injector has to be maintained by periodically mechanically cleaning the injector or soaking it in acid.
The hardness compounds can be removed from the well or surface water by ion exchange, distillation or deionization but these methods are expensive and are often not desired for treatment of potable water. Magnetic devices have been proposed for preventing scale in potable water plumbing. However, these devices have not been shown to function in the more severe situations where a high pH solution is mixed with potable water containing high concentrations of calcium and magnesium hardness.